428 Campbell. — Studies on Garnet op hyte of Selaginella. 
7. The nuclei in the cytoplasm just below the diaphragm 
are smaller and more numerous than those in the basal part 
of the spore. The central body is probably not a nucleolus, 
but a mass of chromatin. . 
8. The masses surrounding the complex of sperm-cells in 
the germinated microspores are probably true cells. 
EXPLANATION OP' FIGURES IN PLATE XIX. 
Illustrating Professor Campbell’s paper on the Gametophyte of Selaginella. 
All figures refer to Selaginella Kraussiana, A. Br. All camera drawings from 
microtome sections. Figs. 1, 2, Leitz, oc. 1, ob. 7 ; Fig. 10, Leitz, oc. 3, ob. 3 ; the 
others Leitz oil im. oc. 1. Ex. exospore ; m. mesospore ; pr. protoplast ; 
n. nuclei ; v. vacuole ; d. diaphragm. 
Fig. 1. Transverse section of young macrospore ; the protoplasmic vesicle, /r, 
still free from the mesospore, m. Two of the four nuclei of the spore are shown 
in the section. 
Fig. 2. Nearly median longitudinal section of an older spore, the protoplasmic 
vesicle in close contact with the mesospore. 
Fig. 3. a, part of a similar section more highly magnified, b, a single nucleus 
seen from above. 
Fig. 4. An older stage ; the cytoplasmic layer has thickened and the nuclei are 
no longer flattened. 
Fig. 5. Surface view of a portion of the cytoplasmic layer with the nuclei. 
Fig. 6. Nearly median section through the apex of the spore shortly before the 
first cell-formation , showing the thickened cytoplasmic layer and nuclei. 
Fig. 7. Section of the cytoplasmic layer of the same spore, near the base. 
Fig. 8. Beginning of cell-formation at the apex of the spore. The areoles are 
still open below. 
Fig. 9. Transverse section through the young prothallium, showing the regular 
form of the central cells. 
Fig. 10. Nearly median longitudinal section of a ripe spore ; the primary 
gametophyte, g, separated from the cytoplasm of the spore-cavity by a diaphragm ; 
many nuclei are scattered through the cytoplasm and the vacuole is still present. 
The outer spore membranes are not shown. 
Fig. 11. Median section of the central part of the prothallium, showing the 
diaphragm separating it from the spore-cavity. 
Fig. 12. Cytoplasm and nuclei from the upper part of the spore-cavity. 
Fig. 13. Part of the basal cytoplasm and nuclei from the same spore. 
Fig. 14. A single nucleus showing the nucleolus-like central chromatin mass, 
composed, apparently, of several crowded granules. 
